1. Field of the Invention
The present invention relates to keyboard devices, in particular, to a keyboard device including a plurality of key tops capable of moving vertically and to a method for manufacturing the keyboard device.
2. Description of the Related Art
Recently, in response to requirements for low-profile keyboard devices, various keyboard devices have been proposed, in which each key top is supported by upper ends of a pair of levers which are linked with each other in a cross, and angles between each linked lever vary in accordance with vertical movement of the key top.
For example, a key switch has been disclosed, in which a pair of the levers are linked at an intersection thereof so that an upper end of the one of levers is rotatably coupled with a key top at a bottom side thereof, and an upper end of the other lever is slidingly mate with the key top at the bottom face thereof. The pair of levers linked with each other support the key top vertically movable.
In such a keyboard device which uses the above-described key switches, when an operator depresses a key top, the pair of levers are pressed downward by being tilted until the key top descends by a predetermined amount, then an elastic member such as a so-called click rubber is deformed by being pressed, and a switch element such as a sheet-shaped membrane switch is closed by the elastic member and thereby switches on.
When a pressing force applied to the key top is released in the switched-on state, the deformed elastic member is restored to the original form by its elastic force, the membrane switch moves into an off-state, and the elastic member raises the tilted levers, thereby pushing the key top to the original position.
By using a pair of the levers which support the key top vertically movable, a superior maneuverability is secured, and the overall thickness can be significantly reduced, whereby the keyboard device can be made low-profile, compared with a conventional keyboard device.
In the known keyboard device, a sheet-shaped membrane switch is mounted on a metallic plate which is provided with a plurality of mating parts formed by cutting and raising the metallic plate. A pair of the levers mate with the mating parts at lower ends of the levers, and a key top is mounted vertically movable to the pair of levers at the upper ends thereof.
In the known keyboard device, there has been a problem in that components of the device cannot be easily assembled, due to wrinkles of the membrane switch being produced and the like, when a pair of the levers are mounted to the mating parts of the metallic plate at the lower ends of the levers, because the membrane switch mounted on the metallic plate is thin.
The metallic plate is provided with a plurality of the mating parts, formed by cutting and raising the metallic plate, for mating with the pair of levers at the lower ends thereof. Various types of such a metallic plate must be prepared because mounting positions and mounting pitch of key switches differ from each other according to the requirements of users.
Therefore, the number of molds for manufacturing metallic plates increases, whereby manufacturing costs of the keyboard devices are increased.
The key tops used for known keyboard devices have been formed thin for reducing the thickness of the overall keyboard devices. Each of the thin key tops has been provided with a rotatable-mating part and a sliding-mating part formed integrally with the key top on a bottom face of the thin key top, for rotatable and sliding-mating with the upper ends, respectively, of a pair of the levers.
These key tops have been each mated with the pair of levers at upper ends thereof in such a manner that each key top is positioned on the pair of levers, and the rotatable-mating part and the sliding-mating part of the key top are mated with the upper ends of the pair of levers. However, since the rotatable-mating part and the sliding-mating part are formed on a bottom face of the key top, it has been difficult to position the rotatable-mating part and the sliding-mating part with respect to the respective upper ends of the pair of levers, whereby a problem has been found in that it is difficult to automate manufacturing.
Accordingly, it is an object of the present invention to provide a keyboard device which is manufactured in a simple manner and is easily manufactured in automated processes and a method for manufacturing the keyboard device, in which a lever-mounting plate mates with a pair of levers at lower ends thereof, and the lever-mounting plate mounted with the pair of levers is mounted to a holding plate by snapping and is mounted on a membrane switch.
It is another object of the present invention to provide a keyboard device of which manufacturing processes are easily automated, in which an actuator is provided which mates with a pair of levers at upper ends thereof in such a manner that the upper ends of the pair of levers are respectively mated with a rotatable-mating unit by snapping and a sliding-mating unit by sliding by moving the actuator horizontally from one position to another position, whereby the pair of levers can be easily mounted to a key top and manufacturing processes can be thereby easily automated.
To these ends, according to an aspect of the present invention, a keyboard device comprises a pair of levers rotatably connected to each other at an intersection therebetween; a key top which is vertically movable and is supported by the pair of levers; an elastic member for elastically urging the key top upward; a switching element for performing switching in accordance with vertical movement of the key top; a lever-mounting plate for mating with the pair of levers at lower ends of the levers, the lever-mounting plate being provided with a mating unit; and a holding plate for holding the lever-mounting plate by snapping at the mating unit of the lever-mounting plate.
The lever-mounting plate may be made of a metallic plate which has a planar base part, the mating unit may include sidewalls opposing each other formed by cutting and raising widthwise ends of the base part, and the holding plate may be provided with a plurality of mounting holes, the mating unit mating with one of the mounting holes by snapping.
The mating unit may be provided with protrusions each protruding toward the outside in the widthwise direction from a part of each sidewall, and the mating unit may mate with the one of the mounting holes by snapping at the protrusions.
The sidewalls of the mating unit continuing from the base part may be each provided with a hook formed by separating a part of the sidewall from the base part, the hook may be formed with an end of the part of the sidewall, the hook being inclined and protruding toward the outside in the widthwise direction, and the hooks may mate with the one of the mounting holes by snapping.
The mounting holes may be rectangular and each mounting hole may be defined by first edges opposing each other and second edges opposing each other, the mating unit may be formed at the widthwise ends toward one side of the base part, a positioning unit may be formed by cutting and raising a portion of the base part toward the other side of the base part, and the mating unit may mate with the one of the mounting holes by snapping at the second edges opposing each other of the one of the mounting holes such that one end face of the mating unit comes into contact with one of the first edges and the positioning unit comes into contact with the other one of the first edges.
The base part may include a first anti-removal part which extends toward the outside from a portion of the base part toward the one side of the base part between the widthwise ends at which the mating unit is disposed and a second anti-removal part which extends toward the outside from the positioning unit which is disposed toward the other side of the base part, the first and second anti-removal parts coming into contact with a bottom surface of the holding plate when the mating unit mates with the one of the mounting holes by snapping.
According to another aspect of the present invention, a method for manufacturing a keyboard device comprises the steps of rotatably connecting a pair of levers to each other at an intersection therebetween; mating the pair of levers with an actuator so that upper ends of the pair of levers vertically move in accordance with vertical movement of a key top; and mating, by snapping, a lever-mounting plate with one of a plurality of mounting holes formed in a holding plate in an upward direction, the lever-mounting plate being mated with the pair of levers at lower ends thereof, whereby the lever-mounting plate is mounted to the holding plate.
In the method for manufacturing a keyboard device, a mating unit may be formed on the lever-mounting plate, the mating unit being capable of mating with the one of the mounting holes by snapping, and the mating unit may be mated with the one of the mounting holes by snapping by lifting the lever-mounting plate disposed under the holding plate.
According to still another aspect of the present invention, a keyboard device comprises a pair of levers rotatably connected to each other at an intersection therebetween; a key top which is vertically movable and is supported by the pair of levers; an elastic member which urges the key top upward; a switching element for performing switching in accordance with vertical movement of the key top; and an actuator coupled with the key top, for mating with the pair of levers at upper ends thereof, the actuator being provided with a rotatable-mating unit including an aperture at which one of the upper ends of the pair of levers rotatably mates with the rotatable-mating unit and a sliding-mating unit including an aperture at which the other one of the upper ends of the pair of levers is slidingly mates with the sliding-mating unit. The apertures of the respective rotatable-mating unit and the sliding-mating unit are open in the same direction as each other.
The rotatable-mating unit may be formed in a U-shape and be disposed at an end of the actuator, and may be provided with a projection formed in the vicinity of the aperture on at least one of two side members opposing each other which form the U-shaped rotatable-mating unit, the projection serving to narrow the aperture.
The sliding-mating unit may be formed in a U-shape and be disposed at an end of the actuator, and two side members may be formed opposing each other and parallel to each other, the two side members forming the U-shaped sliding-mating unit.
The actuator may be made of a metallic plate and be provided with the sliding-mating unit formed by cutting and bending the end of the actuator and the rotatable-mating unit formed by cutting and bending the other end of the actuator.
According to yet another aspect of the present invention, a method for manufacturing a keyboard device comprises the steps of rotatably connecting a pair of levers to each other at an intersection therebetween; mating an actuator with a key top, the actuator being capable of mating with the pair of levers at upper ends thereof, such that the pair of levers vertically move via the actuator in accordance with vertical movement of the key top which is elastically urged by an elastic member; and mating the actuator with the pair of levers in such a manner that the actuator is positioned on the pair of levers at the upper ends thereof and is moved from one position to another position, whereby the actuator mates with the pair of levers at the upper ends thereof.
In the method for manufacturing a keyboard device, by moving from the one position to the other position, the actuator mates by snapping a rotatable-mating unit provided at one end of the actuator with the pair of levers at one of the upper ends thereof and slidingly mates a sliding-mating unit provided at the other end of the actuator with the pair of levers at the other one of the upper ends thereof.
Since the lever-mounting plate is provided with a mating unit for mating with the holding plate by snapping, the lever-mounting plate can be temporarily fixed to the holding plate only by snapping through one-touch operation. Therefore, mounting operation can be easily performed, and manufacturing processes can be easily automated.
The lever-mounting plate having a planar base part is made of a metallic plate. The mating unit is formed with sidewalls which are formed opposing each other by cutting and raising widthwise ends of the base part, and the holding plate is provided with a plurality mounting holes each to mate with the mating unit of the lever-mounting plate by snapping. Therefore, the lever-mounting plate can be temporarily mated with each mounting hole only by snapping the mating unit to the mounting hole, whereby mounting operation is more easily performed.
The mating unit is provided with projections projecting to the outside in the widthwise direction, each formed on the sidewall. Since the mating unit mates with the mounting hole by snapping to the projections, the mating unit is prevented from removal by being reliably mated by snapping to the projections.
The mating unit is provided with hooks each formed by cutting and raising a part of the sidewall connected the base part, the part of the sidewall forming the hook which is inclined and protruding to the outside in the widthwise direction of the base part. The mating unit mates with the mounting hole by snapping at the hooks, thereby reliably preventing the lever-mounting plate from removal.
When a positioning unit is provided at a side of the base part opposite to the side at which the mating unit is provided and the mating unit mates, by snapping, with the mounting hole so as to be in pressure-contact with the second edges of the mating hole opposing each other, one end face of the mating unit comes into contact with one of the first edges of the mating hole and the positioning unit comes into contact with the other one of the first edges, whereby the movement of the lever-mounting plate temporarily mated with the mounting hole by snapping is restricted. The lever-mounting plate is not removed from the mounting hole even when a twisting force is applied to the lever-mounting plate.
When the mating unit of the lever-mounting plate mates with the mounting hole by snapping, the first and second anti-removal parts come into contact with the bottom surface of the holding plate. The pressing force for mating the mating unit of the lever-mounting plate with the mounting hole by snapping is received by the first and second anti-removal parts, whereby the lever-mounting plate can be reliably fixed temporarily to the holding plate.
In a manufacturing method according to the present invention, since the lever-mounting plate is mated in an upward direction with the mounting hole formed in the holding plate by snapping, the lever-mounting plate can be mounted to the holding plate through one-touch operation by snapping. Therefore, a keyboard device, of which mounting can be easily performed and be automated easily, is obtainable.
The lever-mounting plate includes a mounting unit for mating with the mounting hole by snapping. By lifting the lever-mounting plate placed under the holding plate, the mounting unit of the lever-mounting plate is mated with the mounting hole through one-touch operation by snapping. With this arrangement, mounting can be easily performed and be automated easily.